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What Size Fire Extinguisher Do I Need?

Whether you’re moving into a new home or furnishing an office, choosing a fire extinguisher of the correct size is incredibly important.

However, looking at different fire extinguishers can be confusing.

Learning what the codes mean and what different sizes of fire extinguishers can do can help you pick the right one.

What Size Fire Extinguisher Do I Need?

Fire Extinguisher Types

Most of the time, fire extinguisher types are divided by how larger they are. Larger fire extinguishers are, of course, heavier, but they can hold more of the extinguishing agent, which means they can cover a larger area.

It’s important to remember when choosing a fire extinguisher by its weight, this weight only tells you how much the canister can hold when it’s full. If the extinguisher is older, it may not have as much of a charge, so it may not have as much extinguishing agent in it.

Most fire extinguishers, on the other hand, also have a series of numbers and letters printed on them, and this can tell you a lot about the extinguisher’s capabilities and uses.

red fire extinguisher with label

If you’re looking at the numbers and letters on a fire extinguisher classification, you’ll first see a capital A with numbers before it. This tells you how much the water equivalency is.

Every 1A is equal to 1.25 gallons of water. This means that a 2A canister, for example, would be like using 2.5 gallons of water to put out the fire.

This A rating also lets you know that the fire extinguisher will work well against a regular fire made up of dry materials.

The number followed by a capital B tells you the square foot area the extinguisher can cover.

For example, a 50B extinguisher can potentially put out a fire that has spread 50 square feet.

If the fire extinguisher also has the letter C, D, or K at the end of the classification number, it tells you that the extinguisher is designed to be more effective against certain types of fires.

Class C fire extinguishers are safe for use on electrical fires. Class D extinguishers are more commonly used on combustible metal fires. Class K fires are specifically for kitchen fires that feature oil or grease.

fire extinguisher classes
credit: Hamedfire, CC BY-SA 4.0 via Wikimedia Commons

What size fire extinguisher do I need for my house?

Most house fires are relatively small and can be put out quickly, so small or medium-sized fire extinguishers are the best idea.

The living room and main living areas should have a fire extinguisher every 40 feet, and these extinguishers should be between 4 and 10 pounds.

These extinguishers should have at least a 2A:10B:C rating.

You’ll also want to keep a fire extinguisher in the garage, where electrical fires can start.

A 5 to 10-pound extinguisher with a 3A:40B:C rating is a good idea.

The kitchen is also a key spot for a fire extinguisher. Most kitchen fires are very small, so a 2.5 all-purpose extinguisher should work well.

man extinguishing kitchen fire

What size fire extinguisher should I have for my apartment?

If you have a small apartment, you probably only need one all-purpose fire extinguisher.

The fire extinguisher should be about 5 pounds and should be within easy reach from anywhere in the apartment.

Most apartment buildings have sprinkler systems, so you’ll probably only need to put out small fires in an emergency.

However, it’s a good idea to ask about the fire protection the apartment building offers before making a decision about which extinguisher or how many extinguishers to purchase.

fire extinguisher on wall

What size fire extinguisher is best for a business?

Choosing the right fire extinguishers for a business depends on several different factors. First, you’ll need to consider how large the business is and what size the rooms are.

If you have an office or a group of relatively small offices, you’ll probably only need one small fire extinguisher, weighing about 5 pounds, for each room.

small fire extinguisher on table

If the business includes a larger open space, though, you’ll need a fire extinguisher that’s rated to cover that space in the event of a fire.

You’ll also need to consider the type of materials and hazards involved in your business.

Most businesses can use an all-purpose fire extinguisher, but if your business has unique hazards, you might want to ensure that your extinguisher can handle them.

A restaurant, for example, should have a Class K fire extinguisher, which will work well on kitchen grease fires.

Lastly, you need to consider the capabilities of you and your employees. Larger fire extinguishers cover a large area, but they can be incredibly heavy.

If you or an employee can’t lift the extinguisher to use it, it can cause a very dangerous situation. If you have a large, open space that requires a much larger extinguisher, consider purchasing an extinguisher that rolls on a dolly.

This makes it much easier to get the extinguisher into place.

several large fire extinguishers

Fire Extinguisher Shelf Life

Most fire extinguishers last for between five and 15 years.

The specific extinguisher you purchase should have a warranty or date on it that tells you when to replace it.

You should also always replace a fire extinguisher if you use it, even if you haven’t used all of the extinguishing agent.

Some fire extinguishers are rechargeable, which means that, when they pass their expiration date or after they’re used, they can be recharged at a fire station.

Rechargeable fire extinguishers tend to be a bit more expensive than those extinguishers that are only meant to be used once.

fire extinguisher inspection

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